Chess Opening Theory/1. e4/1...e5/2. Nf3/2...Nc6/3. Bb5/3...a6/4. Ba4/4...Nf6/5. O-O/5...Be7/6. Re1/6...b5/7. Bb3

Closed Spanish C79 Spanish game → Closed Spanish → 6...b5 7. Bb3 Black is no longer under any direct threat and may continue to develop. The king and c8-bishop still need to find better squares. Of the three natural moves, 7...Bb7, the Trajković counterattack, is considered a sideline as it gives up the option of ...Bg4. White usually spends a tempo on h3 to prevent ...Bg4, and this move order lets White spend that tempo elsewhere. If Black's going to put this bishop on b7 early on, they normally want to have the other bishop on c5. The main moves both carry threats of different types. 7...d6 is the main line. The d-pawn defends the e5-pawn a second time, freeing the c6-knight to come to a5 and swap off White's precious bishop. Therefore it "forces" the move 8. c3―a move White wants to play anyway―to give the bishop an escape square while preparing to advance the d-pawn. The main line continues 8...O-O 9. h3 and reaches a very theoretically rich position where Black has half a dozen serious continuations. 7...O-O first allows Black to follow up with the Marshall gambit 8. c3 d5!?. Black still has the option of 8...d6, and since in modern times 7...d6 is almost always followed by 8...O-O anyway, at first glance it seems that 7...O-O is a clear winner over 7...d6 in terms of giving Black options. That can't be entirely true, or no-one would play 7...d6. Firstly, the Marshall gambit has been analysed to death, and if there's a way of proving it absolutely sound it hasn't been discovered yet. Secondly, White has a choice of ways of dodging it: 8. h3, steering the game back towards the main line, or 8. a4, eliminating the need to play c3. References See also Ruy Lopez fi:Shakkiaapinen/Peli/1. e4/1...e5/2. Rf3/2...Rc6/3. Lb5/3...a6/4. La4/4...Rf6/5. 0-0/5...Le7/6. Te1/6...b5/7. Lb3